Thermometric electric-circuit closer



(No Model.)

M. MARTIN.

THERMOMETRIC ELECTRIC CIRCUIT CLOSER. No. 286.722.

Patented Oct. I6, 1883.

Fo'y.. I

N. mins. Mmmm. wld-umn. D. c

UNITED STATES PATENT OEEIcE.

MORRIS MARTIN, OF MALDEN, MASSACHUSETTS.

THERMOMETRIC ELECTRIC-CIRCUIT CLOSER.

SPECIFICATION forming part of Letters Patent No. 286,72?, dated October 16, 1883.

(No model.)

T0 @ZZ 107mm/ it may concern.'

Be it known that I, Monnrs MARTIN, of

Malden, in the county of Middlesex, of the Commonwealth of Massachusetts, have invented a new and useful Improvement in llhermometric Electric-Circuit Closers; vand I do hereby declare the saine to be described in the following specification, and represented in the accompanying drawings, of which-- K Figure l. is a l'ront elevation, and Fig. 2 a transverse section, ot' a thermometric electriccircuit closer embodying my invention, the nat-ure of which is defined in the claims hereinafter presented. Fig. is a rear view, and Fig. i a transverse section, of the dial and its stationaryv and revoluble rings. Fig. 5 is a view otthe thermometric mechanism contained in the case ofthe apparatus and for operating the dial-hand.

lThe object oi the instrument shown in the drawings is "to close au electro-galvanic circuit at any d egree ot' temperature indicated on the dial, in order to cause the electro-magnet of such circuit to draw toward it its armature and such armature to operate some mechanism or apparatus connected with or applied to it.

In th eV drawings, A denotes a cylindrical box or ease, provided with a metallic dial, B, which is a ilat annulus, having upon its outer surface divisions and figures indicative of changes ot' temperature. XVithin andconcentrie with the dial is another flat metallic ring, O,which is revoluble within the dial, and besides is provided on its inner side with a metallic Spring, D, to extend from it and lap upon another ring, E, arranged in rear of the/dial and connected therewith by a series of insulators, a c a., ot' vulcanized rubber. The spring D is electrically insulated from the revoluble ring O by Ineans of a block, e, of hard rubber placed between them and fixed to the ring and to such spring. Furthermore, there extends from the spring upward through and somewhat above the ring C, but without being in contact with such ring7 though electrically insulated from it, a metallic stud, b. Fixed in the ring` O, close to the stud, and in a radial line extending through it from the center oi' the dial, is another Inetallic stud, c, they being arranged so that when the metallic hand F ot' the dial may be moved around in Contact with either stud such hand will also touch the other stud. One ofthe electrical circuit wires is shown at G as extending from the dial, and the other at H as extending from the insulated ring E. The hand F is iixed on an arbor, f, that carries a pinion, g, which engages with a rack, l1., adapted to slide lengthwise, the arbor and pinion being arranged in a bracket, It, extending upward from a iiat bar, l, screwed to the case. The said bar, near one end ot' it, is bent upward and has one extremity of a serpentine-shaped bar, m, ot metal tixed to it. This bar goes loosely through a guide, iz, and has a stud or pin, o, extended from it into along slot, p, in another bar, q, which, at its upper end, is jointed to the rack. The said bar q at its lower end is pivoted or hinged to a block, 1', and into which is screwed an adjusting-screw, s, adapted to the bar Z, so as to be revoluble transversely, but not movable longitudinally therein. The screw at its lower end is nicked to receive the end of the blade of a screw-driver, when cxtended intov th e case through a hole made therein in line with the screw. Any increase of the temperature will cause the bar m to expand lengthwise, and thereby move the slotted bar q and cause it to move the rack lengthwise thereof, whereby the pinion will be revolved, so as to cause the hand to be moved about the dial. If, when the two studs of the revoluble ring are set to range with any given division of the scale indicative of the temperature at which it may be desirable to have the circuit closed, and at such temperature the adjusting -screw s be revolved until the hand Inay be carried into contact with the two mctallic studs, such hand, on the temperature falling,will, by consequent contraction ofthe bar m, be moved away from the studs, and so long as the temperature of the surrounding air may be less than that at which the circuit is to be closed, the hand will remain out of contact with the studs; but on the temperature rising to the necessary extent the metallic hand will be carried in contact with the two studs, and consequently the circuit will be closed. In order that the hand Inay be sure to make electrical contact with the studs, there is pivoted at its middle, to the hand, a block or piece of metal, t, which will turn and be sure to touch both studs as the hand may move toward them, so as to carry the piece t into contact with either of tl1em,-and may continue to advance. This piece or block may extend from one or each side of the hand.

I do not claim a therinonietrc dial-hand operative mechanism, as described in either ofthe United States Patents Nos. 89,757 and 251,359, as in neither of them are to be found a sliding` block, an adjusting-screw, and a slotted arm adapted to the rack and spring as in my invention.

\Vhat I claim is as follows:

l. The electric-circuit closer, substantially as described, consisting of the dial, the revoluble ring, and its insulated spring and their two studs, and the insulated ring, all being to operate as explained, with the circuit-Wires and with the dial-hand provided with mech- Vlic block or piece t,with the dial-hand adapt- -ed to operate with the two electric-circuit` studs, arranged as set, forth.

MORRIS MARTIN.

fitnessesz i H. EDDY,- E. BIPRATT. 

